If you can find people to get to know in a context where "exchange" isn't in things with a $ value--like kid-watching etc--then I think it's easier to form relationships of real value. Finding these situations aren't the easiest. Book clubs are great, but these are shrinking in my area.

Real friends can still be rounds, though, at any age if you work hard enough. My best friend died 10 yrs ago, but I do now have another found in a dream work group. Worth the work, believe me!